Siemens SITRANS FUS1010 NEMA-4X/ IP 65 Clamp-On Multi-Function Flowmeter Manual De Usuario

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Successful transit-time flow measurement depends on sonic transmit signals traveling through liquid
and arriving at the receive transducer without excessive attenuation. Receive signals can be scattered
by liquids carrying dispersed particulate matter, either of a solid, non-homogeneous or gaseous na-
ture. This is especially true if the dispersed material is of different sonic impedance than the base
liquid. Liquids that contain an excess of gas bubbles or mineral solids may prove to be unsatisfactory
transit-time applications. However, these liquids are perfectly suitable for Reflexor flowmetering. Liq-
uids containing dissolved gasses or dissolved organic solids will not cause any problems for transit-
time operation.

Most liquids are excellent sonic conductors, regardless of their electrical or optical properties. Al-
though highly viscous liquids exhibit a greater degree of sonic attenuation, System 1010 operates
perfectly with the vast majority of these liquids. The Valc % (signal strength) item on the Diagnostic
Menu is a good indicator of this condition. A low value (under 30) indicates a possible low liquid sonic
conductivity, or improper transducer installation.

The viscosity of the liquid is an important factor. It governs the degree of Reynolds Number compensa-
tion that the flow computer applies to the final rate output. Therefore, flow data errors could result if you
enter an inaccurate viscosity value. Controlotron’s Technical Service Department can provide reliable
viscosity data for most liquids.

Since our clamp-on transducer systems never contact liquid, the issue of liquid compatibility only
applies to entrained gases or mineral solid content that might impair sonic signals  Since System 1010
is designed to measure flow using both transit-time and Reflexor™ techniques, we can safely say that
it will operate most successfully on virtually all liquids.

Undissolved gases, having very low sonic impedance, may cause sonic beam scattering. In large
quantities, they can reduce the sonic signal strength. Small bubbles, caused by cavitation, usually
provoke more signal loss than an equal quantity of large gas bubbles. Usually, the problem can be
alleviated by eliminating the cause. Aeration  may be caused by a mixing  tank, throttling valve cavita-
tion, or air suction upstream of the transducer location.

System 1010 can operate successfully with a larger amount of aeration than any other transit-
time flowmeter. It measures and reports the aeration level as the analog output, Vaer %. This repre-
sents the relative degree of aeration detected within the flow stream. Its computer reports the Vaer
level until it impedes operation and forces a Fault Alarm. The Vaer output accommodates applications
requiring an aeration indicator. The Vaer also appears on the display screen. The aeration percentage
can be used as an alarm relay set-point. You can set the aeration alarm setpoint such that it trips
before aeration reaches a level that impairs flow measurement.